I have a sub panel that has the bonding lug installed, normally i would call this out, however it is a sub panel for a automatic generator system. should the bonding lug be installed, remember this is the land of conduit.
Lord Child I tried hard but couldn’t make anything out in that picture so I will address generators as a whole.
An optional standby generator must meet certain criteria in order to be safe and compliant.
Let’s start with the generator first. If the transfer switch does not break the neutral then the neutral cannot be bonded to the generator frame and no grounding electrode installed at the generator. If the transfer switch does break the neutral then the neutral must be bonded to the frame of the generator and a grounding electrode must be installed at the generator.
The conductors from the generator to the building are feeders and are located outside therefore there must be a disconnect located at the building that is supplied by the generator. This disconnect is required to be rated as service equipment. This disconnect can be the transfer switch if the transfer switch is rated as service equipment. An easy way to tell is, does the transfer switch have an external handle that turns off both the utility and the generator? If no then it is not rated as service equipment.
Between the meter and the transfer switch if the transfer switch is not rated as service equipment there must be a service disconnect. It is in this disconnect is where all the bonding of the neutral and grounding electrode will take place and it will not be bonded anywhere else down stream.
If the generator is supplying a downstream panel (sub panel) then the transfer should not be switching the neutral and the neutral and grounds are separated and isolated but the disconnect at the building from the feeders of the generator is still required.
An easy way to think about this is that bonding of the neutral takes place in one place and in that one place only, the service equipment. It is not allowed to be bonded to the grounds at any other place except at separately derived systems (SDS).
Well Mike how do we know if it is a SDS? The easy answer is, are there any connections between the current grounding conductors or neutral at any point. If the answer is yes then it is not a SDS and isolation is required. For generators this will be found in the transfer switch. Is the transfer switch opening the neutral? If yes then the generator is a SDS, and if no then isolation of the neutral is required.
I hope this helps but should you have questions please let me read them.
Although it is almost completely indiscernible, the picture shows a neutral terminal that is bonded to the enclosure. The problem is, we don’t know much else about the setup.
Is there a transfer switch? Does the generator take over the entire electrical system when it is online? If yes, then the generator panel acts as the service equipment when online, in which case, the bond would be appropriate.
Jeff that is what I figured out after talking to the installer. thanks, yes it was the bonding lug that I was concerned about,
Thanks, will keep for reference.